Recent years have seen an increased demand for inexpensive apparel and the development of new and inexpensive components of construction and method of construction of articles of apparel. In certain instances, there is a demand for apparel that is very inexpensive and, indeed, disposable. New elastomeric materials and methods of incorporating them into portions of the garment have been developed to meet the desire to fit these types of garments to a human form. For example, U.S. Pat. No. 3,639,917 discloses the use of a strip of a heat recoverable elastomeric material to gather the cuff of a disposable hospital gown.
Disposable diapers have been marketed which include an elastic or stretch member in the longitudinal side edges of the disposable diaper to provide elasticity about the leg of the infant when the diaper is applied. Examples of such stretchable fitted diapers which have elastic members disposed in the longitudinal side edges of the diaper are shown in U.S. Pat. Nos. 3,860,003 and 4,050,462. Elastic contraction of the longitudinal sides of the diaper which are the leg and thigh encircling portion of the diaper once placed on an infant compresses the diaper about the leg of the infant. This compression reduces leakage at the leg and upon tightening, leakage is reduced even further. However, if the fit is too tight, irritation can result on this tender portion of the thigh, especially when the diaper is wet. There are also a number of patents which disclose means for making the waist-encircling portion of a disposable diaper elastic for tighter fit of the diaper about the waist of the wearer, for example, as shown and described in U.S. Pat. Nos. 3,995,637 and 3,995,640.
Disposable diapers usually comprise a facing and a backing layer which are substantially co-extensive and a somewhat smaller absorbent core or panel interposed between the facing and backing layers. The facing and backing layers are adhered together about their perimeter by hot melt adhesive or other adhesive material as is well known. In producing stretch or elastic diapers, an elastic member in its stretched or partially stretched state is interposed between the facing and backing sheets along one or more edges of the diaper. The elastic member is adhered either to the facing and/or the backing sheets by adhesive or similar means and allowed to relax to produce elastic sections at the edges of the diaper. An example of a method for inserting elastic members in disposable diapers is disclosed in U.S. Pat. No. 4,081,301.
The incorporation of these elastic members into disposable diapers has increased both the cost of materials used in the diaper and the cost of construction of disposable diapers. With solid elastic members, it is necessary to adhere the edges of the facing and backing sheets together either directly or by their mutual attachment to the elastic member.
When adhesively securing such an elastic member into a disposable diaper, the adhesive chosen must be elastomeric or must be applied in a discontinuous pattern or the glue may make the diaper too stiff to gather.
In commonly assigned co-pending patent application, Ser. No. 210,507 filed Nov. 26, 1980, there is disclosed apertured elastic members which have substantial advantages over other types of elastic members in that they are simpler and more economical to insert and function very well by providing a good fit with a minimum of irritation.
In order to provide the elasticity in the central portion of the side edge of the diaper, it previously had been necessary to insert elastic which, if extended in its stretchable state, would extend the entire length of the side of the diaper. Elasticity is required only in the central portion of the side edges of the diaper, i.e., that portion which encircles the wearer's leg. Thus, in each of the prior art diaper structures, elastic which is either unused or has been rendered non-elastic, resides in the ungathered portion of the side margin and thus elastic material is wasted.
The present invention is an improvement on laminated structures, disposable diapers and a method for inserting the elastic such that there is no waste of elastic material.